The back brake mechanism of drum-type type has the device of automatic adjustment of a gap of brake shoes. Thus the razzhimny level automatically changes the length and by that provides a constant gap between a brake drum and brake shoes. For this purpose between a forward block and a razzhimny level the wedge with a spring being continuation of a razzhimny level takes place. The demanded gap is established after single pressing a brake pedal. If because of wear the course of a block increases, the wedge under the influence of a razzhimny level and a spring falls down. The length of a razzhimny level thus changes and the gap of brake shoes is automatically supported.

PREVENTION

Surely make replacement of all blocks on one axis even if the limit of their wear were reached only by one block.

Removal and dismantling of the back brake mechanism carry out in the following order:

to check thickness of back overlays of brake shoes of a drum-type brake. This check can be carried out, without removing brake drums;

remove the rubber stopper established over an entrance of a cable of the hand brake on a brake board. By means of a portable lamp check thickness of overlays of brake shoes;

will hang out and fix on basic racks a back part of the car;

remove back wheels and switch off the parking brake;

screw-driver uncover the central part of a brake drum;

take fixing шплинт and remove a blocking ring.

unscrew a nut and remove a persistent washer;

remove the external bearing;

turn a brake drum so that openings for bolts of fastening of a wheel settled down at an angle 45 ° from the vertical plane. Having inserted a screw-driver into a forward top opening for a bolt of fastening of a wheel, move up a wedge and release brake shoes;

remove a brake drum. If necessary use a universal stripper;

take a cuff and the internal bearing if he did not act in film together with a drum;

PREVENTION

In order to avoid an exit of pistons from the working brake cylinder do not press a brake pedal at the removed brake drum.

clear internal surfaces of a brake drum, check a condition of its internal surface on wear and damages. If it is necessary, replace a drum;

note a relative positioning of brake shoes and springs, for the subsequent correct installation;

having pressed flat-nose pliers on cups of springs, turn them on 90 ° and remove them together with springs. At turn of cups hold a pin from a reverse side of a brake board;

take brake shoes from the bottom support. Remove brake shoes from the working brake cylinder and disconnect a cable of the hand brake from blocks. To prevent loss of pistons from the working brake cylinder, fix them a wire;

remove the bottom coupling spring of brake shoes;

remove the top returnable spring and a spring of a tension of a wedge;

disconnect a clamping spring of a razzhimny level and remove a razzhimny level together with a wedge;

clear a brake drum, brake shoes and a brake board.

measure thickness of overlays of brake shoes.

PREVENTION

Surely make replacement of all blocks on one axis of the car even if the limit of wear were reached by one block. If blocks are repeatedly established, before removal they are necessary for marking.

Assembly and installation of the back brake mechanism carry out in the following order:

put a small amount of greasing on contact surfaces of the lever of the parking brake and a razzhimny level;

Fig. 12.11. Installation of a forward brake shoe on a razzhimny level

clamp in a vice a razzhimny level, establish a tension spring on a razzhimny level and a forward brake shoe and put on a block a razzhimny level(fig. 12.11);

establish a wedge between a brake shoe and a brake board, thus the nouse of a wedge should be directed to a board;

insert a brake shoe with the lever of the parking brake into a razzhimny level and establish the top returnable spring;

remove a wire holding pistons from loss from working brake cylinders;

connect a cable of the parking brake to the lever of the parking brake;

establish the top part of brake shoes in grooves on pistons of the working brake cylinder;

establish the bottom returnable spring on brake shoes, then establish the lower part of blocks on a support of blocks;

establish a spring of a tension of a wedge;

establish holding pins, press springs and cups. Press on a cup, holding from the back party of a brake board pins, and turn a cup on 90 °, before its accurate fixing;

move a wedge up to create the maximum gap of brake shoes;

insert the internal bearing together with the greasing put on it into a brake drum and establish a cuff;

establish a brake drum;

put on the external bearing greasing and establish it on a pin;

establish a persistent washer and screw a nut;

establish a blocking ring and new fixing шплинт;

establish a cover on the central part of a brake drum;

establish wheels and lower the car;

press once a brake pedal to establish a demanded gap of brake shoes;

similarly replace a brake drum and back brake shoes on the second wheel.